Effect of within Field Soil Variability on Potato Tuber Yield

摘要

Canada is one of the global leaders in potato production, which accounts for 59% of all vegetable farm cash receipts. Currently, management practices are implemented uniformly without considering substantial variation in soil and plant characteristics, topographic features and expected potato tuber yield. These variations emphasize the need for site-specific crop management based on spatial soil variability within the fields. This study was designed to characterize and quantify the spatial patterns of variability in soil properties and potato tuber yield. Two fields were selected in Prince Edward Island (PEI) where a grid sampling strategy was developed at each experimental site to collect soil and crop yield samples. Sampling points and field boundaries in both fields were mapped using a real time kinematics global positioning system. Soil and sensor (DualEM- II and TDR) data were collected four times during a growing season. Soil samples were analyzed for soil organic matter, pH, texture and electrical conductivity. The volumetric moisture content (9v) was recorded at each grid point with time domain reflectometry (TDR). Ground conductivity readings were recorded with DualEM- II conductivity meter at selected sampling points. Soil and crop datawere analyzed using classical statistics to quantify overall variability within fields using Minitab 17. Summary statistics of data for fields in PEI suggest that most of the variables were moderately to highly variable. Semivariograms were produced foreach soil property and crop yield to ascertain the degree of spatial variability between neighboring observations. The soil and crop data were mapped in Arc GIS 10.5 to display the spatial patterns of variability within selected fields. From these maps we concluded that yield was higher in the field where moisture content and electrical conductivity was higher. Characterization of spatial soil variability in potato fields can help in determining effects of soil properties on tuber yield and to draw management zones site specific nutrient management for optimum tuber yield and pollution free environment of potato cultivation.